Counting occurrences of 231 in an involution

Toufik Mansour *
Department of Mathematics
University of Haifa
31905 Haifa
Israel

Abstract    Full Text PDF

We study the generating function for the number of involutions on n letters containing exactly occurrences of 231. It is shown that finding this function for a given r amounts to a routine check of all involutions of length less than or equal to .

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* This is joint work with Sherry H. F. Yan and Laura L. M. Yang (Center for Combinatorics, LPMC, Nankai University, Tianjin 300071, P. R. China).